This project intends to research how complex metabolic pathways originate and evolve. This project will use cutting edge genome sequencing and molecular techniques to elucidate the heritable genetic basis of Baker’s yeast, which has been the selectively evolved to use xylose as a sole carbon source: something vital for second generation biofuel production that wild yeast cannot do. This project will combine detailed molecular characterisation of highly adapted yeast strains with a novel “molecular palaeontology” approach to trace the evolutionary process and identify functionally significant loci under selection. Detailed characterisation of this trait will accelerate the development of future yeast strains and test fundamental evolutionary theories.